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Fourier Series / Fourier Transform Question

  1. Apr 21, 2005 #1
    Hello there,

    Im sure someone on this forum must know how to go about this.
    It is part of an exam question.

    Firstly I must draw a sketch of this pulse:

    v=0 when |t| > a
    v=V0( 1 + t/a ) when -a < t <= 0
    v=V0( 1 - t/a ) when 0 < t < a

    v represents amplitude, V0 represents peak amplitude, t represents
    time and 'a' is a constatnt.

    i can draw the pulse ok, it is just a triangular pulse that goes from
    0 at t = +a and -a to V0 when t = 0.

    The bit I am unsure about is obtaining and sketching the frequency
    spectrum of this pulse. Any ideas?

    Thanks,

    Nik
     
  2. jcsd
  3. Apr 21, 2005 #2

    Hurkyl

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    Isn't there an ethics problem with getting assistance with an exam question?
     
  4. Apr 21, 2005 #3
    maybe if i was in the exam at the time. :smile:
    it's a question from last years signal analysis exam.
    thanks anyway!
     
    Last edited: Apr 21, 2005
  5. Apr 24, 2005 #4
    does anyone have any ideas?
     
  6. Apr 24, 2005 #5

    Hurkyl

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    Well, have you computed the fourier transform?
     
  7. Apr 24, 2005 #6
    i havnt computed the FT. the integration is huge and i get stuck pretty quickly. do you think getting the Freq spectrum could mean getting [tex]a_k[/tex] and [tex]b_k[/tex] coefficients for the fourier series and plotting their magnitudes against [tex]k[/tex]?
     
    Last edited: Apr 24, 2005
  8. Apr 24, 2005 #7

    Hurkyl

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    I'm having difficulty seeing the trouble -- the integral should be something straight out of a calc II class, whether you use sines & cosines as your basis, or you use complex exponentials.
     
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